Transliteration dictionary data where pairs of word written in one language (for example, Japanese) and words written in another language having a transliteration relationship with those words (which are referred to hereinafter as “transliteration pairs”) are registered is used in various applications. For example, the transliteration dictionary data is used when making a product search with a keyword entered by a user on a website (EC site) that sells products (including services) on the Internet.
For example, when  in Japanese Katakana is entered as a search keyword in the above-described product search, a computer that performs the product search refers to the transliteration dictionary data and can thereby show, as search results, not only web pages containing the Japanese Katakana word but also web pages containing the alphabetical word “Beaujolais” having a transliteration relationship with the Japanese Katakana word .
Such transliteration dictionary data has been created (that is, transliteration pairs have been registered in the transliteration dictionary data) by hand or by machine learning based on learning data prepared in advance (for example, see Patent Literature 1 below).